Afghan blasts: Troops named; MILITARY: Failure will encourage terrorists - Army chief.

Byline: Gavin Corden and Margaret Davis

TRIBUTES were paid to the latest British victims of conflict in Afghanistan as the new head of the Army warned that defeat for the international coalition would have an "intoxicating impact" on extremists around the world.

Acting Sergeant Stuart McGrath and Trooper Brett Hall died after they were caught in separate explosions in Helmand province, taking the number of British troops killed since the start of operations to 216.

General Sir David Richards said the failure of the powerful alliance would convince terrorists that "anything might be possible", while inflicting an "enduring grand strategic impact" on Britain's global reputation.

In his first major speech since taking over last month as the Chief of the General Staff, Gen Richards said he was optimistic the coalition would soon "get the formula right".

In an address to the Chatham House foreign affairs think tank in London, Gen Richards said it was essential that Britain saw the mission through to preserve its relationship with the US and honour its responsibilities to the Afghan people.

Failure, he said, could have an "alienating and potentially catalytic effect" on millions of Afghans, while leading to a resurgence of Al-Qaeda-inspired terrorism and the spread of instability to nucleararmed Pakistan. His comments came as tributes were paid to the latest British servicemen to die.

Acting Sjt McGrath, from 2nd Battalion The Rifles, died while on foot patrol in the Gereshk district of central Helmand province on Wednesday.

Trooper Hall, from 2nd Royal Tank Regiment, died in hospital at the Royal College of Defence Medicine at Selly Oak on Wednesday.

He was injured while travelling in an armoured vehicle in the northwest of Helmand on Saturday. Trooper Hall, from Devon, was deployed to Afghanistan in June during the week of his 21st birthday.

Trooper Hall's commanding officer, Lieut Col Marcus Simson, said: "His cheerfulness and his happy smile, alongside his talent and enthusiasm, promised much for the future. Tragically, it's not to be."

Acting Sjt McGrath, aged 28, was born in Princes Risborough, Buckinghamshire.

He leaves a wife Emma, three sons - Ryan, Daniel and Dylan - and baby daughter Niamh, who was born in June after he had been deployed to Afghanistan.

Mrs McGrath said: "Stuart was a loving husband, amazing father, son, brother, cousin and a friend to many."

CAPTION(S):

Blast victim: Trooper Brett Hall. Blast victim: Acting Sergeant Stuart McGrath from 2nd Battalion The Rifles.